It depends on which sizes and what you want the head to do. If both are 125 grn wieghts I like the steelheads much better. They penetrate better and a 1 1/4" head has a pretty big cut. In the 100 grn weight you have to decide what you want, Max penetration is larger cutting diameter. The 100 grn steelhead penetrates great, but only has a 1 1/8" cut. The 100 grn spitfire has a 1 1/2" cut but doesn' t penetrate nearly as well as the steelhead. Spitfire blades are much sharper than the steelheads and you don' t need rubber bands to hold the in place. Both are good heads, but In the 125 grn wieght class the steelhead wins hands down. In the 100 grn class you have to decided what is most important to you.